Season 3 Episode 9: "Psychiatry Failure? The Serotonin Theory of Depression Lacks Evidence!"-Joanna Moncrieff, MD

In this episode of Making Therapy Better, Dr. Bruce Wampold sits down with psychiatrist and researcher Joanna Moncrieff for a deep and challenging conversation about one of the most influential ideas in modern psychiatry: the belief that depression is caused by a chemical imbalance in the brain.

Drawing on decades of research and her landmark work on the serotonin theory of depression, Joanna explains why the evidence for a serotonin deficiency as the cause of depression remains inconsistent and unconvincing. She walks through major strands of biological research, placebo-controlled antidepressant trials, and the methodological issues — including unblinding and expectancy effects — that may inflate the apparent benefits of antidepressant medications.

Bruce and Joanna explore why how antidepressants work matters for informed consent, highlighting emotional numbing, psychoactive effects, and the small differences typically observed between drugs and placebo. The discussion moves beyond neuroscience to examine the sociology of psychiatry, including professional incentives, pharmaceutical marketing, DSM changes, and how the “chemical imbalance” narrative became embedded in public understanding despite weak empirical support.

The episode also addresses real-world prescribing practices, the role of human support and clinical contact, and why depression may be better understood as a meaningful human response to life circumstances rather than a discrete brain disease. Looking ahead, Joanna shares her concerns about emerging drug trends — including psychedelics — and warns about the risks of commercialization overshadowing psychotherapy and human care.

This episode invites clinicians and the public alike to rethink long-held assumptions about depression, medication, and recovery — and to consider more hopeful, human-centered ways of understanding emotional suffering.

Joanna Moncrieff is Professor of Critical and Social Psychiatry at University College London and author of Chemically Imbalanced: The Making and Unmaking of the Serotonin Myth. Bruce Wampold is Emeritus Professor at the University of Wisconsin–Madison and author of The Great Psychotherapy Debate.